4. Learn the language
Sure you speak English but the question is, is it British? They have tons of words that means completely different with what you might have known. If you’re an Aussie, you might give them a laugh when ask to borrow a thong.
Also, don’t get into argument when they say it’s autumn season during your visit but you actually insist that it’s fall. It pays to read and learn a few words and phrases to be aware of the British terminologies.